printf（）方法是用于格式化的方法。

2，源代码

public class Main {

    public static void main(String[] args) {

        System.out.printf("%d This is a format String ", 123);

        boolean myBoolean = true;
        char myChar = '@';
        String myString = "hiro";
        int myInt = 50;
        double myDouble = 1000;

        System.out.printf("%b", myBoolean);
        System.out.printf("%c", myChar);
        System.out.printf("%s", myString);
        System.out.printf("%d", myInt);
        System.out.printf("%f", myDouble);

        System.out.printf("Hello %10s", myString); //
        System.out.printf("Hello %-10s", myString); //

        System.out.printf("You have this much money %.2f", myDouble);
        System.out.printf("You have this much money %.1f", myDouble);
        System.out.printf("You have this much money %f", myDouble);

        System.out.printf("You have this much money %+f", myDouble);
        System.out.printf("You have this much money %020f", myDouble);
        System.out.printf("You have this much money %,f", myDouble);

    }

}

Java 教程